Triethylamine → 3-(3,5-di-tertiary butyl-4-hydroxyphenyl)-1-(2-ethoxycarbonyloxyethyl)-1H-pyrazolo[3,4-b]-pyridine

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Reaction Steps

To a solution of 3.7 g of the compound of Example 43 in 20 ml of chloroform is added 1.5 g of triethylamine, and to the mixture with stirring at -10°--2° C. is added 1.4 g of ethyl chlorocarbonate dropwise. After completion of the addition, the whole mixture is stirred at 0° C. for 3 hours, and then at room temperature for 2 hours. The reaction solution is washed with water, dried and concentrated, and then the resulting residue is recrystallized from isopropyl ether to give 3.8 g of 3-(3,5-di-tertiary butyl-4-hydroxyphenyl)-1-(2-ethoxycarbonyloxyethyl)-1H-pyrazolo[3,4-b]-pyridine as white crystals, melting at 103°-105° C.

Provenance & Evidence